let y be your total moneyx is the number of cup of food you can buym is the cost per cup of food to feed the animalb is the cost to enter the petting zoo
y = mx + bsubstitute the given values
12.50 = 2.50x + 7.50solve for x
12.50 - 7.50 = 2.50x5 = 2.50xx = 5 / 2.50x = 2 cups of food you can buy